What you need to know about the kona low Saturday on the Big Island: Entire island now under flash flood warning; spots on Ali‘i Drive added to growing list of road closures

Editor’s note: This page will be continuously updated throughout the day.

A powerful Kona low continues sweeping through the Hawaiian Islands, bringing strong winds and heavy flooding rainfall. The entire Big Island was put under a flash flood warning shortly after 9 p.m. Saturday, March 14, as heavy rains continued to fall.

Hawaiʻi County officials say residents should continue to avoid all unnecessary travel because of significant risks of flash flooding and strong, locally damaging winds.

The storm produced heavy rainfall and strong wind gusts Saturday throughout large areas of Hawaiʻi Island, as well as flash floods that closed multiple sections of Highway 11 in Kaʻū. causing the county to urge residents in those areas to shelter in place.

Some areas in Kaʻū received 10 to 15 inches of rain in 24 hours. Moderate to heavy rainfall was expected to remain in place over Kaʻū through Saturday evening, leading to significant flash flooding.

Heavy rainfall and strong winds also caused road closures and property damage Saturday in Puna, Kona and Kohala.

Peak wind gusts of between 50 to 60 mph, with a few locations seeing gusts up to about 70 mph.

Hawaiʻi Fire Department personnel rescued three residents from a flooded home near Whittington Beach Park. They were relocated Saturday to the Nāʻālehu shelter. Big Island first responders also rescued two visitors from a stranded vehicle near South Point.

A high-water vehicle from Hawaiʻi National Guard was sent to Nāʻālehu Fire Station to assist with emergency response.

A flood watch and high wind warning remain in place for all of Hawai‘i Island, and flash flood warnings for Puna and Ka‘ū as well as the Kona area. A high surf advisory for south-facing shores of the island also remains in effect.

“County of Hawaiʻi crews and our state partners are working hard to reopen roads and keep our residents safe,” said Hawaiʻi County Mayor Kimo Alameda in a weather update. “The risk of flash flooding and strong, damaging winds remain[s] through Sunday, and we urge residents to avoid all nonessential travel for the rest of the weekend.”

Weather conditions could escalate further with bands of heavy showers continuing Sunday to move over Hawaiʻi Island. Areas with the highest potential rainfall are in Kona, Kaʻū and Kohala.

Strong wind gusts could also continue Sunday, particularly in Kona and Puna.

Current weather advisories

Flash flood warning: New. In effect for the entire Big Island until 1 a.m. Sunday, March 15. Radar indicated at 9:13 p.m. heavy rain over all of the island, falling at 1 to 3 inches per hour. Several stream gauges remain above flood warning thresholds islandwide. Flash flooding was ongoing, with reports of highway closures and flooding in local communities.

Significant and life-threatening flooding is expected in drainages, streams, rivers, roads, properties and other low-lying areas. Multiple public road closures are expected, as well as the possibility for landslides in areas of steep terrain.

Hawai‘i County Civil Defense advises:

• Flooding is life-threatening.
• All residents in flood-prone areas should remain on alert for possible flooding. Move to high ground as necessary.
• Drive with caution. Be on alert for runoff, ponding of water, debris and poor visibility.
• Do not attempt to cross flowing water in a vehicle or on foot; turn around, don’t drown.
• Road closures could be instituted with little or no warning.
• Remember: if lightning threatens your area, the safest place to be is indoors.

High surf advisory: Originally in effect until 6 p.m. Saturday, forecasters with the National Weather Service in Honolulu report surf along south-facing shores has decreased to below advisory criteria and will continue to gradually decline throughout tonight. Therefore, the high surf advisory for south-facing shores of the Big Island is canceled.

Flood watch: In effect islandwide through Sunday night (March 15).

High wind warning: Southwest winds of 30 to 40 mph, with gusts up to 70 mph, are now expected through Sunday evening (March 15) as the high wind warning in effect for lower elevations of the Big Island was extended by the National Weather Service. Areas most at risk are communities north and east of steep mountain terrain, including Kona and Ka‘ū. Southwest winds of 55 to 75 mph, with gusts up to 110 mph, are also forecast through Sunday evening for the Big Island summits of Mauna Kea and Mauna Loa.

Winter storm warning: Extended until 6 a.m. Monday (March 16) for summits of Mauna Kea and Mauna Loa above 12,000 feet elevation. Blizzard conditions are possible, with additional snow accumulation of 12 to 20 inches and winds potentially gusting to more than 100 mph. Travel could be very difficult to impossible. Blowing snow will significantly reduce visibility, with periods of zero visibility at times.

Power outages: About 20,400 customers, or 22% of Hawaiian Electric’s total customers on the Big Island, remained without power as of the utility’s 9 p.m. update, all of them in areas being impacted by strong winds, thunderstorms and heavy rain. That’s the entire island as of the last update from the National Weather Service in Honolulu, which issued a flash flood warning for the whole island in effect until 1 a.m. Sunday. The majority of the outages are in the Puna area. Unfortunately, most who are currently without power are likely to remain out overnight.

Water restriction

Hawai‘i County Department of Water Supply asks customers effective immediately in North and South Kona, North Kohala, Pāhoa and Mountain View to restrict water use to essential needs only because of current and anticipated prolonged power outages.

Customers islandwide also are asked to conserve water during the storm.

The county Water Supply Department relies on Hawaiian Electric power to operate wells and booster pumps to distribute water. Backup generators are used at a limited number of well sites, but these emergency generators cannot fully replicate Hawaiian Electric’s power grid.

An extended power outage because of the storm and adverse weather could deplete portions of the department’s water systems and leave customers with low pressure or no water.

To reach the DWS, please Call 808-961-8050 during normal business hours, 808-961-8790 for after-hour emergencies or email to dws@hawaiidws.org.

Open emergency shelters

• Puʻuʻeo Community Center, 145 Wainaku St., Hilo.

• Panaʻewa Park, 100 Ohuohu St., Hilo.

• Papāʻaloa Park Annex, 35-1994 Government Main Road, Papāʻaloa.

• Honokaʻa Gym, 45-541 Lehua St. Honokaʻa.

• Waimea Community Center, 65-1260 Kawaihae Road, Waimea.

• Ikuo Hisaoka Gymnasium, 54-382 Kamehameha Park Road, Kapaʻau.

• Waikōloa Elementary School cafeteria, 68-1730 Hooko St., Waikōloa.

• Kekuaokalani Gym, 75-5500 Kuakini Highway, Kailua-Kona.

• Yano Hall, 82-6156 Māmalahoa Highway, Captain Cook.

• Nāʻālehu Community Center, 95-5635 Hawaiʻi Belt Road, Nāʻālehu.

• Robert N. Herkes Gym, 96-1219 Kamani St., Pāhala.

• Pāhoa Neighborhood Facility, 15-2910 Kauhale St., Pāhoa.

In response to several closures on Highway 11, the county opened another shelter at Cooper Center in Volcano to assist residents unable to get home.

Residents and visitors using a shelter should bring their own supplies, including sleeping bags, food, water, necessary medications and pet food.

All shelters, except Waikōloa Elementary School, are pet-friendly. Pets must be kept in a crate or carrier.

Road closures

• Kaʻalāiki Road (Cane Haul Road) in Ka‘ū between Pāhala and Nā‘ālehu closed because of flooding.
• Waipi‘o Valley Road in Hāmākua is open to residents and farmers only.
• Wood Valley Road in Pāhala in Ka‘ū because of flooding.
• Highway 11, between the 62 and 56 mile markers, because of flooding; no alternate routes available. Barricades placed in areas where moving water is passing over the road.
• Kohala Mountain Road, also known as Highway 250, tree down at 20-mile marker. State crew responding.
• Highways 190, 11 and 130: Fallen trees cleared.
• Highway 130 near 3-mile marker barricades in place because of ponding on the highway.
• Highway 11, between Pinao Street and Kaʻaluʻalu Road in Ka‘ū, because of flooding. No alternate routes available.
• Highway 11, between the 50-mile marker and Kamani Street in Ka‘ū, because of flooding. No alternate routes available. 
• Highway 11 between the 50- and 51-mile markers in Pāhala.
• Highway 11 between the 56- and 62-mile markers in Kawa.
• Highway 11 between the 65- and 66-mile markers in Hāʻao Springs Road/Waiʻōhinu.
• Aliʻi Drive (Aliʻi Bypass) in Kailua-Kona, between Halekiʻi Street and Nāpōʻopoʻo Road, because of extreme flooding. Both lanes closed.
• Aliʻi Drive, between Kaʻahumanu Place (Kailua Pier) and Sarona Road, because of extreme flooding. Both lanes closed.
• Highway 11, near the intersection of North Glenwood Road at the 22-mile marker, is open to all traffic.
• Queen Kaʻahumanu Highway (Highway 19) in Kona, near the Mormon temple, because of flooding on the roadway. Use alternate route.
• Roads in the Kawaihae area are closed because of flooding. This includes ʻAkoni Pule Highway at the 4-mile marker; Kawaihae Harbor, Spencer Beach Park areas; and the area of Queen Kaʻahumanu Highway (Highway 19), between Hāpuna Beach and Kawaihae Road. Use Highway 190 and Kawaihae Road as alternative routes.  

Closures and cancellations

• All Hawai‘i County offices closed through Sunday for all nonemergency services
• All Hawai‘i County beach parks closed through Sunday.
• All Hawai‘i County transfer stations, solid waste facilities and landfills closed through Sunday. County officials ask and urge residents to not leave rubbish at the closed transfer stations.
• Hilo Municipal Golf Course closed through Sunday.
• Panaʻewa Rainforest Zoo and Gardens closed through Sunday.
• All Hawai‘i state parks; visit the Hawaiʻi State Parks web page for updates about storm-related closures.
• Several areas inside Hawai‘i Volcanoes National Park, including Mauna Loa summit
• All Hawai‘i public libraries
• All public and charter schools as well as many University of Hawai’i campuses statewide
• Hawaiʻi Judiciary facilities and services, as well as state offices 
• All fixed route Hele-On buses and paratransit services are canceled again Sunday. Check the Hele-On X page for updates. Call 808-640-1020 for additional paratransit updates.
• Camping permits at all Hawai‘i County parks are canceled through Monday morning (March 16).

Big Island summits

Maunakea Visitor Information Station updated shortly before 7 a.m. today on its Facebook page that stormy conditions are reported on Mauna Kea’s summit this morning, with 77 mph winds and 96 mph gusts — “down from 118mph!!!”

Click here to check current weather conditions.

The summit access road is closed; road crews were assessing the situation to determine if it is safe to go up and clear the snow and ice from the roadway.

Stay informed

Hawaiʻi County will provide updates as conditions evolve. Residents can receive emergency notifications by signing up for Hawaiʻi County Civil Defense alerts.

View the Hawaiʻi County Hazard Impact Map for additional weather-related information.

Stay updated about weather by visiting the Big Island Now weather page and the National Weather Service Honolulu forecast office website.